Cover for yarn tensioning wheel



Oct. 5, 1965 E. J. sAxl.

COVER FOR YARN TENSIONING WHEEL l u e m W L V"- w e a/ www fw Tw/s l .a .HHHHWHHH E@ T :G 5T .1| MM T I 6c Filed Feb. 18, 1963 Zay Tfn Oct. 5, 1965 E. J. sAxL.

COVER FOR YARN TENSIONING WHEEL 2 Sheets-Sheet 2 Filed Feb. 1B, 1965 mmmmwmm www- T n.555*.......56...3. .a.........Qg

United States Patent O 3,209,608 CUVER FR YARN TENSIONING WHEEL Erwin J. Saxl, Harvard, Mass., assigner to Tensitron, Inc., Harvard, Mass., a corporation of Massachusetts Filed Feb. 18, 1963, Ser. No. 259,035 4 Claims. (Cl. 74-230.7)

This invention relates in general to yarn tensioning devices, and more particularly to wheel or pulley types of traction devices for maintaining a certain desired tension on yarns, wires, tapes, and similar materials, during various operations.

A tension control system of the type for which the invention is primarily intended, for running yarns, consists essentially of a detection device which senses variations inthe tension of the yarn, and a traction wheel which the yarn passes around and which may be braked or driven in such a way as to compensate for the detected variations. For such a system to function accurately the traction wheel must have adequate frictional engagement with the yarn to transmit the tensioning force required without slipping. At the same time it is necessary to avoid damaging the surface of the yarn or permanently deforming materials such as line wire.

The principal object of this invention is to provide a cover for traction wheels which has a high resistance to slippage and yet can be safely used on delicate materials. Another object is to provide a simple and inexpensive method of manufacturing Vsuch covers. Other objects, advantages, and novel features will be apparent from the following description.

In the drawings illustrating the invention:

FIG. l is a side elevation of the apparatus used to make a Wheel cover according to the method of the invention, the dipping tank being shown in cross-section;

FIG. 2 is a fragmentary side elevation of a mandrel used to make the wheel cover, illustrating the cover in cross-section in an intermediate stage of manufacture;

FIG. 3 is a fragmentary side elevation of a completed wheel cover;

FIG. 4 is a fragmentary cross-section of the lower part of the wheel cover of FIG. 3 after its removal from the mandrel; Y

FIG. 5 is a fragmentary side elevation of a wheel with the cover in place, the cover being shown in cross-section;

FIG. 6 is a side elevation of a mandrel for making a cover to be used on a capstan, the partly fabricated cover being shown in cross-section;

FIG. 7 is a cross-section of a cover made on the mandrel of FIG. 6;

FIG. 8 is a side elevation of a capstan with the wheel cover of FIG. 7 installed, the cover being shown in crosssection;

FIG. 9 is a side elevation of a mandrel for making a cover for a roll used for tape, a partly fabricated cover being shown in cross-section; and

FIG. 10 is a side elevation of a drag roll with a cover made on the mandrel of FIG. 9 installed.

The mandrel 29, shown in FIG. 1, is in the form of a wheel having a peripheral groove 21, bounded by flanges 22 and 23. A pair of narrower grooves 24 and 25 are disposed one on either side of groove 21 and the remaining peripheral surface of the mandrel consists of bevelled surfaces 26 and 27.

According to the method of the invention, the mandrel is mounted on a shaft 28 which is rotatably supported on posts 29 and 30. A tank 31 is disposed below the mandrel and is partly lled with a bath 32 of liquid latex or similar material. The tank is preferably lled to a level to just cover the bevelled surfaces 26 and 27 at the lowermost point of the mandrel.

The mandrel is rotated, by hand or any suitable mechanism, until a coating of latex of the desired thickness is built up around its entire periphery. The mandrel may be coated by rotating it once through the bath, but it is preferably to use a thin solution and rotate the mandrel a number of times to insure uniform thickness of the deposited layer. After coating, the mandrel is removed from the bath, the first coating is allowed to dry supercially, that is until the outer skin is solidified to a certain extent. The mandrel is then placed in a second bath of latex or similar material and rotated in the same manner to build up a second layer of the desired thickness. One of the baths contains an appropriate pigment, or both may be colored, so as to produce two layers of contrasting colors such as black and yellow. To speed up the deposit of the coating, an insulating plate 36 may be placed under the tank 31 and an electric charge applied between the tank and the mandrel. Alternatively, the tank may be of insulating material and an electrode 33 of inert conductive material may be placed in the bottom and a charge imposed between the electrode and the mandrel.

The deposited coating 34, consisting of layers 34a and 3417, is dried until it is partly solidified, but still deformable. A serrated wheel 35 is then run along the portion of the coating which overlies groove 21. The portions of the coating which overlies surfaces 26 and 27 are then rolled up, as indicated in dotted line in FIG. 2, into grooves 24 and 25. The coating is then cured by heat or other well-known methods.

The mandrel is made of material which has a wetting affinity for the solution material and yet will permit the cured cover to be stripped off readily. Aluminum and stainless steel are suitable for the purpose. When the cover has been cured, it is stripped off the mandrel. The finished cover 40, as shown in FIGS. 3 and 4 is a ring having hollow flanges 4tlg and 4Gb bounding circumferential groove 40e and inwardly extending rim portions 40d and 40e terminating in beads 40jc and 40g. The cover has serrations 41 across the base of the groove.

The cover 4) is used on a lightweight wheel, generally indicated by the numeral 42, having a conical ange 42a, which ts into flange 40a, and a number of tabs 42b which fit into flange 40h. The yarn on which the wheel is used runs in groove 40C of the wheel cover. The wheel may be driven, in any convenient manner, to draw yarn along, or may be braked to apply a desired amount of tension to the yarn during various operations. The wheel may be used, for example, with a magnetic braking device of the type shown in my previous Patent No. 3,022,025.

The cover provides good traction and also cushions the yarn from the rigid wheel. The serrations at the base of groove 4th: increase the traction, but as the cover is made of relatively soft rubber, the serrations will not crimp or deform materials such as fine wire. When the cover becomes unduly worn, the inner layer of contrasting color is exposed and gives a visual indication that the cover should be replaced.

The cover shown in FIGS. 6, 7 and 8 is intended for use on a capstan in cases where, because of either the tension required or ,extreme slipperiness of the yarn, it is desirable to carry the yarn more than one turn around the traction wheel. The mandrel 45 has bevelled end portions 46 and 47 and adjoining grooves 48 and 49. The central portion 50 is an elongated cylinder having a spiral rib 51. A coating consisting of two layers 52 and 53 is formed in the manner previously described, by rotating the peripheral surface of the mandrel through successive baths of latex.

After partially drying the coating, the portions overlying surfaces 46 and 47 are rolled up into grooves 48 and 49. When the cover has been curved, it is stripped from the mandrel and turned inside out. The finished cover, generally indicated by the numeral 54, has beads 54a and 54h at the ends, and an intermediate portion 54C with a spiral groove 55 around the outside. The cover is used on a capstan 56 and the yarn runs in the groove which is here shown as suitable for accommodating two turns. It is understood that the mandrel may be designed to form a cover with a groove passing around as many times as desired.

The mandrel 57 shown in FIG. 9 has bevelled end portions 58 and 59, adjacent grooves 60 and 61, and a cylindrical central portion 62 with a knurled surface. The mandrel is coated as previously described with two layers 63 and 64, and the cover is completed by rolling the portions of the coating overlying surfaces 58 and 59 into grooves 60 and 61. When the cover, generally indicated by the numeral 65, has been cured, it is stripped from the mandrel and turned inside out. The cover has beads 65a and 65b and an intermediate portion 65e with a knurled outer surface. This cover is especially suitable for use with tapes and may be mounted on a roll having the conguration of the capstan 56 in FIG. 8.

The covers here disclosed provide good traction and at the same time serve as acushion between the yarn and the traction wheel and prevent damage to the yarn. The two color, two layer arrangement gives a visual indication that the cover should be replaced before it wears through and allows the yarn to come in contact with the rigid wheel. The beads around the edges of the cover, being thicker and thus more rigid than the intermediate portion keep the cover in shape and hold it securely on the wheel. Covers of this type may be made, according to the method here described, to fit a wide variety of traction wheels or pulleys by using suitably shaped mandrels.

It is understood that this type of cover may be used on traction wheels intended for yarns, threads, wires,

tapes and similar materials. The term filamentary material as used in the appended claims is intended in the general sense and is intended to include all yarn-like and tape-like materials.

What is claimed is:

1. A traction device for tensioning ilamentary materials comprising a wheel and a generally ring-shaped cover of soft elastic material surrounding and engaging said wheel, said cover comprising an inner layer and an outer layer, and said layers being of different colors, said cover having a relatively thin iiexible central filament-engaging portion and edge portions of a thickness greater than that of the central portion.

Z. A traction device as described in claim 1, said cover having a pair of V-shaped peripheral flanges and a groove therebetween constituting said tilament engaging portion, and transverse serrations in said groove.

3. A traction device as described in claim 1, said central portion having a spiral filament engaging groove of curved cross-section therein.

4. A traction device as described in claim 1, said central portion having a knurled outer surface.

References Cited by the Examiner UNITED STATES PATENTS 283,356 8/83 Painter 74-230.7

636,941 11/99 Barron 74-215 X 1,376,742 5/21 Burnett 74-230.7 1,632,512 6/27 Serva 74-230.7 1,792,187 2/31 Robertson 18-58.4 1,907,345 5/33 Cornish 74-230.7 2,151,566 3/39 Sander 74-215 2,638,632 5/53 Glazer 18-58.4 2,743,810 5/56 Armstrong 74-230.7 X

DON A. WAITE, Primary Examiner. 

1. A TRACTION DEVICE FOR TENSIONING FILAMENTARY MATERIALS COMPRISING A WHEEL AND A GENERALLY RING-SHAPED COVER OF SOFT ELASTIC MATERIAL SURROUNDING AND ENGAGING SAID WHEEL, SAID COVER COMPRISING AN INNER LAYER AND AN OUTER LAYER, AND SAID LAYERS BEING OF DIFFERENT COLORS, SAID 